Lubrication is an important aspect of maintaining machinery in proper operating condition. Machine elements such as bearings, journals, shafts, and joints require proper lubrication between their moving surfaces to decrease friction, prevent contamination, reduce wear and dissipate heat. Improper lubrication is likely to lead to premature component wear and component or system failure.
When determining the optimal lubrication between moving machine elements, many factors should be considered. These factors include the mode of operation of the machine, the type of machine element to be lubricated, the environment of the machine, the operating speed of the machine, the lubricant""s viscosity, the lubricant""s temperature, the lubricant""s ingredients, and the lubricant""s condition.
Prior art lubricators, such as the TRICO OptoMatic oiler, supply a constant level of lubricant within a lubricant reservoir to a machine element. The lubricant level is predetermined for the particular application and cannot be changed during the operating time of the machine to which the constant level lubricator is attached. Although this type of lubricator provides reasonable performance in many steady-state operations, multiple variables can create unacceptable operating conditions and lead to premature wear, or even failure, of machine elements. The variables include xe2x80x9conxe2x80x9d and xe2x80x9coffxe2x80x9d operating modes (machine cycling), oil viscosity, machine speed, lubricant temperature, lubricant condition, and lubricant vessel pressure.
Other devices, such as the TRICO Hydrolert indicate by LED signals the status of the equipment""s lubrication such as lubricant condition within acceptable levels, lubricant condition at the upper limit of acceptable levels, and lubricant condition immediate action required. This device is effective because an operator is signaled only when the lubricant condition is at the upper limit of acceptable levels or if immediate action is required. This reduces maintenance costs and productivity is enhanced.
With specific regard to lubricant relative humidity, or saturated relative humidity, one prior form of lubricant qualitative control utilized an in-line water removal filter. Another form of lubricant qualitative control is to dilute the existing amount of lubricant with a fresh supply of lubricant, reducing the overall lubricant moisture content by introducing a portion of lubricant with a lower moisture content. Still another form of moisture removal is to expose the air surrounding the lubricant to a desiccant material that removes humidity from the air.
The system of the present invention relates generally to the field of lubrication and specifically to the field of devices which deliver a lubricant to a machine element, such as a bearing in a pump.
The system of the present invention provides continual on-line monitoring that eliminates the need for expensive repetitive lubrication checking and time-consuming laboratory oil sampling. Designed for installation on rotating equipment or other lubricant reservoirs, the system of the present invention provides real time information on lubricant variables such as lubricant water content, with the added flexibility of providing real time information and control of other variables such as temperature, viscosity, and particulate matter.
The present invention is directed at lowering lubricant water content to acceptable levels. It has been discovered that moisture removal from oil is an important objective to achieve optimum lubricant condition. Lubricants such as oil have an initial moisture content, and often the initial moisture content is unacceptable. Additionally, harsh machine operating conditions such as pump wash-downs and condensation occurring during changing plant temperature and humidity conditions can contribute to potentially harmful lubricant moisture levels.
If the lubricant is not agitated such as during an off operating mode, a continuous oxygenated layer forms a barrier on top of the lubricant. This oxygenated layer prevents moisture from both entering and leaving the lubricant. When the lubricant is agitated, such as during an xe2x80x9conxe2x80x9d equipment operating mode, the oxygenated layer is broken. xe2x80x9cDryxe2x80x9d air, or air with moisture significantly removed, assists in withdrawing the moisture from the oil by a continuous moisture equilibrium interaction between the agitated lubricant and the dry air above the lubricant. It has also been found that an increase in dry air temperature increases the rate of moisture removal from the lubricant.
The present volumetric lubricant dispenser controls water content in a lubricant to provide optimum operating conditions and extend the useful life of lubricants. An automatically controlled system is adjusted by means of a microprocessor that receives input from various system sensors and adjusts the lubricant humidity level accordingly through an air drying process, that, in turn lowers the lubricant moisture level. In the automatic mode, the entire system is constantly monitored.
The present volumetric lubricant dispenser is designed to control the water content of lubricant to a rotating element or machine part or other lubricant reservoir. The rotating element may include a bearing or a journal or the combination of the two. In a typical application, a bearing includes an inner and an outer race. Between the races a plurality of rolling elements are positioned, usually balls. If the outer race is attached to the bearing housing, the inner race and the rolling elements are rotated into and out of a lubricant reservoir. The reservoir is maintained within the bearing housing.
For the purpose of qualitative lubricant control, the present invention may be described as a system intended for controlling lubricants, both mineral (natural) and synthetic based, by measuring the condition characteristics of the lubricant, including water or moisture content.
Accordingly, an apparatus for qualitative lubricant condition control and monitoring may include but not be limited to the following illustrative description. The apparatus comprises at least one lubricant condition-sensing module. The module may be of any suitable type for sensing a desired lubricant characteristic; in this case water or moisture content. The lubricant sensing module is communicatively coupled to a qualitative control mechanism. For example, the qualitative control mechanism could be a microprocessor. The qualitative control mechanism is also communicatively coupled to at least one response mechanism, e.g., an air pump or compressor. The qualitative control mechanism is capable of actuating at least one response mechanism in response to a signal received from at least one lubricant condition-sensing module and interpreted by the qualitative control mechanism.
A method of reducing moisture content of a lubricant contained in an enclosed space is also disclosed and is performed by agitating the lubricant, providing a humidity sensor in fluid communication with the enclosed space, measuring the humidity of the enclosed space and comparing the humidity measurement with a pre-selected humidity level, introducing dry air into the enclosed space if the humidity level equals or exceeds the pre-selected humidity level, until the saturated humidity level is less than the pre-selected humidity level.